package com.kaifamiao.demo.d0802.pm;

public class Demo02 {

    Integer a; // 引用类型  null

    int b; // 基本类型  0

    public static void main(String[] args) {
        Demo02 demo = new Demo02();

        System.out.println(demo.a);
        System.out.println(demo.b);
    }
}
